They are wrong, The picture of the fish they display is that of a Ki Shusui.

I refer to the book by Takeo Kuroki “ Mordern Nishikigoi”, page 235.

Quote :

Kinds of yellow Doitsu include the Ki Matshuba Doistu and Ki Shusui. The difference between the two is that the latter not only have dark blue scales, but blue shading running from the dorsal down to the lateral line, while the former, have the blue limited solely to the line of scales along the dorsal ridge.

A BC

A= Ki ShusuiB= Ki Matshuba DoitsuC= Baby Midorigoi

This is what he wrote on page 229;

Quote :

Midori-goi was found among the babies of Ki Shusui, and was bright green when smaller. The color is fading as it grows, so that both sides of the body are now green, but the other parts are light brown. A Midori-goi should have a green body and a clear head.

David, I suppose the best way to work out an answer for you original question is to work out if you what you are really wanting to know.

Is the sanke a show qualitry example of a sanke ? - no not at allIs the sanke worth buying? - this depends on the price, health of fish, and what your expectations are from your fish.

Are you after a fish that will develop or do you just plan to have a good pond fish? I can only asume the latter considering the fish in question. My advice would be buy absolutely anything you want as long as the fish is healthy, you like it, and the price is fair.

Guess the best way to analyse the fish is according to your expectations and not ours.